Dyestuff intermediates



Patented July 3, 1928.

UNITED STATES PATENT OFFICE.

FRITZ BALLAUF, FRIEDRICH MUTE, AND ALBERT SCHMELZER, 0F ELBERFELD, GER-MANY, ASSIGNORSTO GRASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y.

DYESTUFF- INTERTIEDIATES.

No Drawing. Application filed January 16, 19 25; Serial No. 2,926, andin Germany January 24, 1924.

bazoloic acids themselves, i. e.,

, /CO0H Carbazol-l-carboxylic acid. NHU

Carbazol-Zcarboxylie acid Carbazol-S-carboxylic acid COOH do notcondense readily with nitroso-phenols to the corresponding indophenols,we have found that by reacting primary and secondary amines in thepresence of condensing agents with carbazoloic acids, carbazoloicacid-arylids of the following type are obtained:

(in which formula Xstands for hydrogen or a hydrocarbon radical and Yfor a hydrocarbon radical) and these condense easily withnitrosophenols. The different carbazol-carboxylic acids can be used,though the.

carbazol-land the carbazol-Q-carboxylic acids being the most easilytechnically accessible are particularly valuable for our process.Thecarbazol-1-carboxylic acid can be produced according to Ciamician(Gaz. 12, page 272) and the carbazol-Q-carboxylic acid is described byBorsche (Ber. 40 page 381). Aliphatic as. Well as aromatic primary andsecondary amines can be condensed with the acids. In the examples givenherein we describe the condensation of carbazol-carboxylic acids withamines such as dimethyl-amine, para-toluidine, 2- amido-carbazol, butour invention is not limited to the use of these amino bodies.

Example 1.42 parts by weight of carbazol-Q-carb-oxylic acid aredissolved in 1000 parts of toluol and at the boiling temperature oftoluol, dimethyl-amine is bubbled through this solution with asimultaneous .and gradual addition of phosphorous trichloride, until nomore free carbazoloic acid can be detected in the solution. The solventis now distilled off, the residue digested with water and the waterinsoluble carbazoloic acid-arylid filtered oil". The2-earbazoloicacid-dimethyl-amid is obtainedby recrystallization fromnitrob'enzol in thick needles melting with slight decomposition at 198C; by prolonged heating the melt becomes clear and transparent. TheQ-carbazoloicacid-dimethyl-amid is insoluble in most organic solvents aswell as in water, caustic alkali solutions and dilute acids, but easilysoluble in more concentrated sulfuric acids (from 6066) and in .hotnitrob-enzol; in cold nitrobenzol it is only sparingly soluble.

The amid as obtained in the above is dried and dissolved in 2750 partsby weight of concentrated sulfuric acid 66. 27.5 parts by Weight ofnitrosophenol are dissolved in 460 parts of concentrated sulfuric acidof about 64 Be, both solutions are cooled and mixed. After a short whilethe reaction probably has the formula:

BOO-a r:

i I 1 on H- G11: The indophenol dissolves alcohol with a reddish bluecolor and-in concentrated sulfuric acid with a greenish blue color. Inalkaline solution. the indophenol 1s readily reduced by sodium-sulfideor hydrosulfide NaSH) to the corresponding leuco-indophenol. The lattercan also be obtained directly by pouring the reaction mass in sulfuricacid upon a solution of caustic soda diluted with a large amount of ice,reducing this solution and precipitating the leuco-indophenol byacidification.

Ewample 2.Carbazol-3-carboxylic acid is treated in toluol solution withpara-toluidin and phosphorous-tri-chloride as condensation agent. The3-carbazoloicpara-toluid is insoluble in water, alkali solutions anddilute acids, quite difiiculty soluble in most organic solvents butsoluble in concentrated sulfuric acid. The arylid so obtained isdissolved in concentrated sulfuric acid, the solution cooled and amolecular proportion of nitrosophenol added. The indophenol formsreadily and quickly. The sulfuric acid solution is diluted with a largeamount of ice and the precipitated indophenol filtered off. When driedit forms a blue powder, soluble in concentrated sulfuric acid with agreenish blue color, and when reduced in alkaline solution with sodiumsulfide orhydrosulfide, forms the corresponding leuco compound.

Example 3,- -Carbazol-1-carboxylic acid is condensed in boiling toluolsolution with molecular proportions of Q-amido-carbazol, usingphosphorous-tri-chloride as a condensing agept. After distilling off thesolvent as a liasaiigessdwvah 'water and filtered off. he1-carbazoloig1p id-2-carbazolamid is insoluble in mostorgamfibl'ventsaswell furic acid of concentrations of above B. The drytoluid as obtained in the above 'is dissolved in 3200 parts sulfuricacid containing 90% H 80 cooled to about 0 C. and 27.5 partspara-nitroso-phenol dissolved in 450 parts 90% sulfuric acid are added.As soon as all of the nitroso-phenol has reacted, the reaction mass ispoured upon ice, filtered and the filter cake washed with water. Thedried 2-carbazoloic-acid-para-toluid indophenol is a blue powder,soluble in concentrated sulfuric acid with a blue color; in alkalinesolution it is readil reduced b sodium sulfide or hydrosul dc to theeuco com 'ound.

, e claim 1. In processes of making carbazoloicacid-aryhd-indophenolsthe steps comprising reacting aromatlc amino bodies in the pres ence ofa condensation agent with carbazolcarboxylic acids and condensing the soobtained carbazoloic-aeid-arylids with nitrosophenols. V

2. In rocesses of making carbazoloicacid-arylld-indophenols the stepscomprising reactin aromatic amino bodies in the presence o hos horoustri-chloride with carbazol-carliox ic acids and condensing the soobtained car azoloic-acid-arylids with nitroso-phenols in sulfuric acidsolution.

3. In processes of making indophenols of carbazoloic-acid-amidecompounds the steps comprising reacting organic amines having areplaceable h drogen atom linked to the nitrogen, inthe presencepf'acondensation agent, with carbazol-carboxylic acids and as in water,caustic alkali and dilute acids; condensing the so-obtainedcarbazoloic-acidit is readily soluble in concentrated sulfuric acids(from (SO-66 B.). The arylid so obtained is dissolved in concentratedsulfuric acid and condensed with molecular proportions of nitrosophenol.The formation of the indophenoldproceeds uickl and the solution is poure"on ice, t e in ophenol recipitating. Filtered off and dried, it IS ablue powder soluble in concentrated sulfuric acid with a greenish bluecolor; by reduction with sodium sulfide or sodium hydrosulfide inalkaline solution it yields the correspondleuco-compound.

wmnple 4.42 parts by weight of carbazol-2-carboxylic acid are suspendedin 900 parts toluol and 22 parts para-toluidin added. The reaction massis heated to 70 (1, 10.5 partsphosphorous tri-chloride added and boiledfor several hours. The solvent is steamed off, the residue digested withwater and the insoluble arylid filtered oif. The 2-carbazoloic-para-toluid forms shiny elongated leaflets, melting at 294C. It is'insoluble amide coinpoundsQfvith nitrosophenols. v

4. In processes 0 makingindophenols of carbazoloic-acid-amide compoundsthe steps c'omprisin reacting organic amines having a replaces. 1ehydrogen atom linked to the nitrogen, inthepresence of phosphoroustrichloride, with carbazolzcarboxyllc acids and condensing theso-obtained"carbazoloic-acidamide compounds with nitrosophenols i n fromreddish-blue to' blue color and being reduced in alkaline solution withsodium sulfide or hydrosulfide to the corresponding ,leuco compounds.

6. As new products the indophenols of carbazoloic-acid-amide compoundswhich are substantially identical with products obtainable by reactingorganic amines, having replaceable hydrogen atom linked to thenitrogent, with carbazol-carboxylic acids and .reduced with sodiumsulfide or hydrosulfide condensing the carbazoloic-acid-amide comto thecorresponding leuco compounds. pounds so obtained with nitrosophenols,In testimony whereof we have hereunto 10 which indophenols arereddish-blue to blue set our hands.

I powders, soluble in concentrated sulfuric I FRITZ B'ALLAUF.

acid with from reddish-blue to blue color FRIEDRIGH MUTH. and which inalkaline solution are readily ALBERT SCHMELZER. Y

